This invention relates to a machine tool suitable both for the use of rotary cutting tools, e.g. milling cutters, and the use of stationary cutting tools, e.g. turning tools.
British Pat. No. 1,448,749 shows a lathe which has a headstock spindle for the support of a workpiece, a slide linearly positionable relative to the headstock spindle, an indexable turret supported on the slide, a stationary tool, viz. a turning tool, secured to the turret at one index station thereof, and a rotary cutting tool, viz. a milling cutter, provided at another said station. The headstock spindle is continuously rotatable for performing a turning operation on the workpiece by said turning tool. Further, the headstock spindle is, optionally, rotationally positionable, i.e. it is rotatable about its axis into predetermined angular positions, so that, for milling operations, the workpiece can be presented to the milling cutter at different angles about said axis. Regarding driving of the milling cutter, it is known practice in machines such as the above, to provide the cutter on a mounting releasably securable to the turret and including a continuously rotatable spindle having the cutter secured to one end thereof and provided at the other end with a driven gear meshing with a driving gear provided on the turret. Different such mountings have to be provided for milling operations requiring different angles between the axis of the headstock spindle and that of the cutter spindle. Also mountings different from those of the milling cutters have to be provided for those of any said turning tools.
It is among the objects of this invention to avoid the need for different said mountings and thereby reduce the cost of tooling and improve the versatility of the machine.